A large excavator on Monday morning tore into the metal sheathing of the paint building at the former Ford plant in St. Paul, launching the demolition of the plant's major structures after more than 80 years of making cars in the Highland Park neighborhood.

In brief remarks before the teardown began, Mayor Chris Coleman said it was "a bittersweet day" because of the thousands of jobs Ford had provided over the years. But he said that housing and new jobs will replace the 150-acre plant site in times to come.

City leaders worked for years to persuade Ford to continue work at the plant, but the company closed it in December 2011 after 86 years in operation.

"Today is a day that the landscape of St. Paul fundamentally changes ... But it is a day that marks a giant step forward for the Highland community, for the city of St Paul and for the region," Coleman said.

The paint building will be razed first, followed by the main assembly building and then the training center built in 1999. Most of the structures should be down by the end of 2014.